Looper mechanism for sewing machines



sept. 22, 1925. 1,554,363

J. R. MOFFATT Loopn MECHANISM FOR sEwxNG MACHINES Filed sept; 26, 1921 2 suena-snm 2 Patented Sept. 22, 1925.

unirsi)A STA-rss PATENT OFFICE. l

JAMES n. MOFFATT, or CHICAGOl ILLINOIS, AssIeNoR rro UNION sPECIAL MACHINE CoivniANsr, `or CHICAGO, ILLINoIs, A CORPORATION or ILLINOIS.

LOOPER MECHANISM FOB vSEWING MACHINES.

Application inea september 2e, 1921. serial No. 503,429.

To all whom t may concern.'

Be it known that I, JAMES a citizen of the United States, residing at Chicago, in thecounty of Cook, State of Illinois, have invented certain new and useful `Improvements in Looper Mechanism for Sewing Machines, of which the following is a description, reference being had to the accompanying drawing, and to the figures of reference marked thereon.

The invention relates to new and useful improvements in looper mechanisms for sewingy machines, and more particularly to a thread carrying looper having a needle avoiding movement as well as a movement into and out of the needle thread loop.

An object ofthe invention is to provide a'variable looper movement wherein allof the movements imparted to the looper are derived from a' single lever. i

A further object of the invention is to provide va looper mechanism of the above type wherein the fulcrum for the actuating lever whichfimparts all the movements to the looper, may be shifted endwise of the lever for varyingthe movements imparted to the looper through said lever.

A still further object)V ofk the invention is I to provide means for positively shifting the connection of the fulcrum to the lever and for holding said fulcrum in adjusted positions.

These and other objects will in part be obvious and will in part be hereinafter more fully disclosed. i

In the drawings which show by way of illustration one embodiment of the invention- Figure 1 is a view partly in side elevation and partly in vertical section showing a portion of a `sewing machine embodying my improvements; n

Fig. 2 is a sectional view on the;l line 22 of Fig. 1; l

Fig. 3 is a sectional yview on 4the line 3 3 of Fig..2, and i Fig. 4 is a perspective view of the rear end of the looper supporting shaft show-- ing the manner of mounting the s ame and also showing detached the operating lever for imparting vmovements to the looper supporting shaft and the fulcrum supportlng arm therefor.' l The invention is directed to a machine R. MoFFAfr'r,

having a work supporting arm for stitching tubular articles, and particularly a type of machine wherein the work supporting arm is carried by a vertically extending member, and wherein the looper or'loopers are car ried by a looper supporting shaft which' is not only oscillated, but moved endwise through a single lever, said lever being connected intermediate its ends to a` fulcrum arm. This fulcrumarm is capableof endwise movements, oscillating movements and turning movements, so that an eccentric member attached to the lever not only oscillates the lever so as to move the looper supporting shaft back and forth endwise, but also moves the lever endwise so as to oscillate the looper supporting shaft.

A machine of this general type, and to which my invention is shown applied, is disclosed Vin the patent. granted to Lansing Onderdonk, December 18, 1906, No. 839,077. I have only shown sufficient of the machine inthe drawings to make clear the invention, it being understood that reference will be made to said patent for an understanding of the complete machine. i

The machine includes a horizontally eX- tending arm 1 having a vertically extendingy f postor supporting member 2 rising from the end thereof, and on the upper end of this vertically extending post is a forwardly projecting work supporting arm 3. The needles 4 and 5 are carried by a needle bar v6 which is, reciprocated in the usual way,

foot 7. The material is fed off from the end ofthe work support by means of a feed dog 10. .This feed dog 101s carried by a feed bar Y11.V vrThe feed bar11 is ypivoted at 12 to linksl13.. These links 13 are pivoted at their lower ends to a lever 14. The lever 14 is fulcrumed to swing about a support 15l and is oscillated on said support by means of a link 16. This link 16 is connected to an eccentric ystrap l17 which cooperates with an eccentric. on the shaft 18. When the shaftirotates this link 16 through the lever'14 raises and lowers the feed bar 11. The feed bar at its rear end slides back and forth on the supporting pin 19. The. feed bar is moved endwise by means of a link Which is adjustably connected to a lever V21 pivoted at 22. This lever is oscillated by means of a link 23 Which in turn is connected to an eccentric strap 24 cooperating vvith an eccentric' on the shaft 18. This feeding,` mechanism per se forms no part of the present invention, brit is shown, described and claimed in my copending` application, Serial lo. 503,430, filed of even date herewith.

Cooperatingvvith the needle 4 beneath the work support is a looper 25. Cooperating with the needle 5`is` a looper 2G. These loopers 25 and 26 are thread carrying looper's and are mounted in a looper carrier 27 which in turn is fixed to the end of a shaft 28. This shaft 28y is mounted s as to oscillate freely and also move endrvise in suitable bearings, one near the forward end of the arm 3 and another in the vertical post 2. In Fig. 4 of the drawings, the sleeve bearing` in the post 2 is indicated at29. Fixed to the looper supporting shaft 28 is a collar ,30 which is clamped thereon by means of a clamping sorev 31.` Projecting from the colla-1' 30 is an arm which is provided with a ball 33. A lever 34 is 'provided with a bracket 35 at itsnpperend having a socket 36 for the ball 33. A cap plate` 37 also engages the ball 33 an'd forms a ball socket therefor. The lever is providedwvith a headk 38 at its loiver end having a ballsocket 39 adapted to engage a ball 40 on a crank arm 41. This crank arm 41 is carried by a sleeve 42 which is fixed to the end of the shaft 18.

ly'iounted on s'aid leverintermediate the ends thereof is an adjustable sleeve 43. Said sleeve 43' has a laterally projecting lug 44 into Which is threadedka screw 45. This screw 45is provided With Aa slotted head 4G and a collar 47 spaced slightly therefrom so as 'to engage between the forked arms 48 formed integral ivi-th the bracket 35. These collars prevent the screvv from moving endvvise 'relative to the bracket so that upon turning the screvv, the sleeve 43 Will be positively shifted endvvise ofthe lever 34.V Said sleeve 43 is a split sleeve, and is positive-ly clamped to the lever by means of a` screw 49. Projecting from the sleeve 43 is a perforated lug 50. A fulcrnm arm 51 is provided vvith a forked end adapted yto straddle the sleeve and is secured thereto by means ofthe pin 52. This fulcr'um arm 51 is freely mounted in a sleeve 5,3 so that the arm may move endwise inthe `sleeve, and can oscillate in said sleeve. The sleeve 53 is in turn rigidly secured to a head 54 carried by the stem mounted in a bearingsleeve 56 in the vertical arm 2. the outer end of the stem J55 'is4 acollar 57 and a locknut 58. This stem 55 isfree to oscillate in the bearing 56 which permits the sleeve 53 to oscillate about the center of the stem 55 as an axis.

The operation of the machine is thought to be obvious from the above description. As the shaft 18 rotates, the lever 34 at its lower end will move in a circle. The fulcrum of the lever` is confined to movements up and down in a vertical plane so that the lever 34 oscilla-tes on said fulcrum and moves endwise with the fulcrum. This irnparts an elliptical movement to the ball 33 and gives in turn to the loopers both the needle avoiding movement and a movement into and out 'of the needle thread loops. So far as the operation ofthe loopers are concerned, they are similar to that 'set forth in the Onderdonk patent referred to above.

The present invention is directed particularly to the means for shifting,` the fulcr'un in order to vary the extent of movement given to the looper. By loosening the screw 49, and turning the screw 45, the sleeve 43 may be moved endwise of the lever 34. This shifting of the sleeve is positively obtained by the turning of the screw 45, and the 'connection' of lthe fulcriun to the lever is positively secured in its adjusted positions by means of the screw 49. When this sleeve is move'd endWise of the lever, it will vary the amount of lateral movement imparted to the loopers, and this i's accomplished without any changing of the movement of the looper into and out of the needle thread loops.

Tt is obvious that minor changes in the details of construction and the arrangement of the parts may be made Without departing from the spiritI of the invention as set forth in the appended claims.

Having thus described the invention, What l clai'm as new and desire to secure by Letters-Patent, is

1. A looper mechanism for sewing machines including in combination, a looper, a loo'per supporting` shaft carrying said looper, a lever constructed and arranged so as to impart to said looper 'supporting shaftoscillating and endvvise movements for giving to the looper a needle avoiding movein'e'nt and a loop taking` and shedding movement, a single fulcrum -support for said lever, and means for shiftingthe position of the fulcrum support on the lever for varying the extent of lateral movement only imparted to the looper.

2. A looper mechanism for sewing machines including' in combination, av looper. a loope'r 'supporting shaft carrying" said looper, a lever connected to said l'ooper, an operating' shaft extending' at right angles to the looper supporting,- shaft, averank 'carried by said operating; shaft to Which said lever is connected, a single 'fulcrum support connectedlto said lever intermediate the ends thereof and *arranged "so that said lever `Will oscillate said looper supporting shaft and move the same endwise, and means for shifting the position of the fulcrum support on the lever for varying the extent of lateral movement only imparted to the looper.

3. A looper mechanism for sewing machines including in combination, a looper, a looper supporting shaft carrying said looper, a lever connected to said looper, an operating shaft extending at right angles to the looper supporting shaft, a crank carried by said operating shaft to which said lever is connected, a single fulcrum support connected to said lever intermediate the ends thereof and arranged so that said lever both oscillates said looper supporting shaft and moves the same endwise, means for positively shifting the position of the fulcrum support on the lever for varying the extent of lateral movement only imparted to the looper from said lever, and means for locking the fulcrum support in its adjusted positions.

4. A looper mechanism for sewing machines including in combination, a looper, a supporting shaft therefor, an operating shaft arranged at right angles to the supporting shaft for the looper, an armV projecting from the looper supporting shaft having a ball on its outer end, a crank carried by the operating shaft and having a ball on its outer end, a lever having ball socket connections with the arm and the crank, a fulcrum supporting arm connected to the lever intermediate its ends so as to oscillate in a plane lengthwise of the lever, an oscillating sleeve in which said arm is mounted and capable of moving freely endwise, said sleeve being mounted to oscillate about an axis parallel with the looper support, and means whereby the connection of the fulcrum arm to the lever may be shifted.

5. A looper mechanism for sewing machines including in combination, a looper, a supporting shaft therefor, an operating shaft arranged at right angles to the supporting shaft for the looper, an arm projecting from the looper supporting shaft having a ball on its outer end, a crank carried by the operating shaft and having a ball on its outer end, a lever having ball socket connections with the arm and the crank, a fulcrum supporting arm connected to the lever intermediate its ends so as to oscillate in a plane lengthwise of the lever, an oscillating sleeve in which said arm is mounted and capable of moving freely endwise, said sleeve being mounted to oscillate about an axis parallel with the looper support, a screw connected to the lever so that the same may be rotated without endwise movement, a sleeve on the lever to which said fulcrum arm is pivoted, said screw having a threaded connection with the sleeve whereby the turning of t-he screw positively moves the sleeve endwise of the lever.

6 A looper mechanism for sewing machines including in combination, a looper, a supporting shaft therefor, an operating shaft arranged at right angles to the supporting shaft for the looper, an arm projecting from the looper supporting shaft having a ball on its outer end, a crank carried by the operating shaft and having a ball on its outer end, a lever having ball socket connections with the arm and the crank, a fulcrum supporting armconnected t0 the lever intermediate its ends so as to oscillate in a plane lengthwise of the lever, an oscillating sleeve in which said arm is mounted and capable of moving freely endwise, said sleeve being mounted to oscillate about an axis parallelwith the looper support, a screw connected to the lever so that the same may be rotated without endwise movement, a sleeve on the lever to which said fulcrum arm is pivoted, said screw having a threaded connection with the sleeve whereby the turning of the screw positively moves the sleeve endwise of the lever, and means for positively clamping the ysleeve to the lever.

In testimony whereof, I affix my signature.

J AMES R. MOFFATT. 

